The invention relates to a grinder, particularly for the grinding of frozen or fresh meat, with a worm conveyor, a drive shaft, and a set of blades which comprises a carving blade arranged after the worm conveyor, a perforated disc arranged at a fixed distance after the carving blade, and a driven blade which is arranged between the carving blade and the perforated disc, the set of blades being clamped with a cap nut in the worm housing.
Grinders of this type, in which the driven blade is inserted in an intermediate space created by a spacer ring between the perforated disc and the carving blade, are well-known. In this case it must be ensured that the driven blade has only very little play so that the cutting process is not impaired. A grinder designed in such a way is used for the cutting of frozen meat. If fresh meat is also to be cut by such a grinder, it has been necessary until now to replace the sets of blades and possibly also the worm conveyors, which are adapted to these sets of blades. In practice, the cutting tools and the worm conveyors usually have to be replaced several times daily, which entails a not inconsiderable degree of effort.
The invention is based on the object of designing a grinder of the type described above, so that it is suitable both for the cutting of frozen meat and for the cutting of fresh meat without retooling and on which, in addition, the set of blades can be used for a much longer period of time.
According to the invention, this object is achieved in that the distance between the carving blade and the perforated disc is the same or slightly greater than the radial extension of the blades, and that the blade is axially displaceable on the drive shaft and pressed against the perforated disc with a predetermined initial load.
With a grinder according to the invention, the blade pressed with spring-loading against the perforated disc first of all achieves uniform cutting results, even with advancing wear. Second, it is also possible to process both fresh and frozen meat with good quality with the same set of blades without retooling. The reasons for this are that, owing to the constant preset cutting pressure, the cutting tools are guided with precision, the cutting pressure resulting from the components of the spring and of the product itself, thus yielding a product-specific cutting pressure. Since the blade automatically adjusts itself with advancing wear, cutting results remain constant over a very long period of time. Moreover, the excessive clamping of the set of blades, as conventionally occurs with the manual turning of the cap nut, is also eliminated. All of these factors also yield the advantage that the set of blades is not damaged by brief dry running. Furthermore, the initial loading of the blade is adjustable, so that the cutting pressure can be continuously adapted to different processing conditions.